Frozen precipitation and/or other debris may accumulate on the top surface (e.g., the roof) of a vehicle while the vehicle is stationary (e.g., stopped or parked) or moving. Such frozen precipitation may include any one or more of, for example, snow, ice, sleet, freezing rain, and hail.
Examples of vehicles include road vehicles, such as passenger or cargo vans, trucks, trailers, semi-trailers, tractors for hauling semi-trailers, recreational vehicles, and structures being transported via trailer (e.g., mobile homes and pre-fabricated housing units). The top surface of such a vehicle may have tens or hundreds of square feet of surface area, such that the mass of accumulated debris may be substantial.
When the vehicle is in motion, the accumulated debris may blow or fall away from the vehicle, which may create hazards for other drivers. Such hazards may include reduced visibility, danger of impact by large solid masses (e.g., falling blocks of ice), and/or road obstacles (e.g., large masses of fallen snow or ice).
Many jurisdictions (e.g., countries, states, cities, and counties) have statutes and/or regulations in place that require the removal of accumulated snow and/or ice from a vehicle before it is operated on the road. The problem of snow and ice accumulation on vehicles is also the subject of a report issued by the American Transportation Research Institute in December 2008.
Manually clearing snow and/or ice from the top surface of a vehicle (e.g., using a shovel or manually operated scraper) can be dangerous. The standard height of a semi-trailer is thirteen and one-half feet, and the height of the wheel assembly can add several feet to this distance. Mounting a ladder and/or climbing to reach a roof at such a height can be especially dangerous under the slippery conditions that typically accompany the presence of frozen precipitation. Such manual work is also time-consuming and tiring: the surface area of the top of a typical semi-trailer is eight-and-one-half by fifty-three feet (i.e., 450.5 square feet), such that the total weight of several inches of accumulated snow can easily exceed one thousand pounds. In some climates, re-accumulation of snow and ice can occur frequently (even daily) during the winter season.
Other ways of removing accumulated frozen precipitation from the top surface of a vehicle include driving the vehicle under a stationary scraper to clear the surface or using heat and/or chemicals to melt the frozen precipitation. However, facilities to practice such removal methods are typically expensive to install and thus are typically available only at limited locations. Such use of chemicals may also present environmental concerns.